From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52945) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwpH9-0000Ui-Vq for qemu-devel@nongnu.org; Mon, 25 May 2015 06:06:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YwpH4-0002Yt-QU for qemu-devel@nongnu.org; Mon, 25 May 2015 06:06:27 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:35535) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YwpH4-0002Yk-HP for qemu-devel@nongnu.org; Mon, 25 May 2015 06:06:22 -0400 Received: by pdea3 with SMTP id a3so67046997pde.2 for ; Mon, 25 May 2015 03:06:22 -0700 (PDT) Message-ID: <5562F416.2040301@ozlabs.ru> Date: Mon, 25 May 2015 20:06:14 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1432023962-32406-1-git-send-email-nikunj@linux.vnet.ibm.com> <1432023962-32406-5-git-send-email-nikunj@linux.vnet.ibm.com> <5561B504.9050604@ozlabs.ru> <87a8wt8d8i.fsf@abhimanyu.in.ibm.com> In-Reply-To: <87a8wt8d8i.fsf@abhimanyu.in.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH v5 4/4] spapr_pci: populate ibm,loc-code List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Nikunj A Dadhania , qemu-devel@nongnu.org, david@gibson.dropbear.id.au Cc: qemu-ppc@nongnu.org, agraf@suse.de, mdroth@linux.vnet.ibm.com On 05/25/2015 02:58 PM, Nikunj A Dadhania wrote: > Alexey Kardashevskiy writes: > >> On 05/19/2015 06:26 PM, Nikunj A Dadhania wrote: >>> Each hardware instance has a platform unique location code. The OF >>> device tree that describes a part of a hardware entity must include >>> the “ibm,loc-code” property with a value that represents the location >>> code for that hardware entity. >>> >>> Populate ibm,loc-code. >>> >>> 1) PCI passthru devices need to identify with its own ibm,loc-code >>> available on the host. In failure cases use: >>> vfio_::. >>> >>> 2) Emulated devices encode as following: >>> qemu_::. >>> >>> Signed-off-by: Nikunj A Dadhania >>> --- >>> hw/ppc/spapr_pci.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++-------- >>> 1 file changed, 69 insertions(+), 12 deletions(-) >>> >>> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c >>> index 12f1b9c..dd77119 100644 >>> --- a/hw/ppc/spapr_pci.c >>> +++ b/hw/ppc/spapr_pci.c >>> @@ -769,6 +769,61 @@ static uint32_t spapr_phb_get_pci_drc_index(sPAPRPHBState *phb, >>> return drck->get_index(drc); >>> } >>> >>> +static char *spapr_phb_vfio_get_loc_code(sPAPRPHBState *sphb, PCIDevice *pdev) >>> +{ >>> + char *path = NULL, *buf = NULL; >>> + char *host = NULL; >> >> Why not put them all in one line (or split into 3 lines :) )? > > Sure. > >> >> >>> + >>> + /* Get the PCI VFIO host id */ >>> + host = object_property_get_str(OBJECT(pdev), "host", NULL); >>> + if (!host) { >>> + goto err_out; >>> + } >>> + >>> + /* Construct the path of the file that will give us the DT location */ >>> + path = g_strdup_printf("/sys/bus/pci/devices/%s/devspec", host); >>> + g_free(host); >>> + if (path && !g_file_get_contents(path, &buf, NULL, NULL)) { >>> + goto err_out; >>> + } >>> + g_free(path); >>> + >>> + /* Construct and read from host device tree the loc-code */ >>> + path = g_strdup_printf("/proc/device-tree%s/ibm,loc-code", buf); >>> + g_free(buf); >>> + if (path && !g_file_get_contents(path, &buf, NULL, NULL)) { >> >> If path==NULL, you'll return bad buf. > > Oh, got it wrong. > >> >> >>> + goto err_out; >>> + } >>> + return buf; >>> + >>> +err_out: >>> + g_free(path); >>> + return NULL; >>> +} >>> + >>> +static char *spapr_phb_get_loc_code(sPAPRPHBState *sphb, PCIDevice *pdev) >>> +{ >>> + char *buf; >>> + char devtype[16] = "qemu"; >> >> I still like "const char *s = "qemu";" better. > > Yes, was waiting for respin after review. > >> >> >>> + >>> + if (object_dynamic_cast(OBJECT(pdev), "vfio-pci")) { >>> + buf = spapr_phb_vfio_get_loc_code(sphb, pdev); >>> + if (buf) { >>> + return buf; >>> + } >>> + snprintf(devtype, 4, "vfio"); >> >> With "const", you could just do devtype = "vfio". >> >> Also, >> ===== >> char devtype[16] = { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa }; >> snprintf(devtype, 4, "vfio"); >> printf("%x %x %x\n", devtype[2], devtype[3], devtype[4]); >> ==== >> >> produces on my laptop (gcc 4.9.2) this: >> >> [aik@aik ~]$ ./a.out >> 69 0 ffffffaa >> >> >> Is it different where you tested this? >> >> >>> + } >>> + /* >>> + * For emulated devices and VFIO-failure case, make up >>> + * the loc-code. >>> + */ >>> + buf = g_strdup_printf("%s_%s:%02d:%02d.%1d", >> >> How is "1d" different here from just "d"? If @devfn>10, all digits will be >> printed. > > A device can have only 8 functions, right ? Yes. It is "%d" (decimal) so "1" is a minimum field length anyway ("1" only makes sense for strings imho). And if a function number is bigger than 9, print() will print all digits, not just the last one. So %d==%1d but I would never grep for "%02d:%02d.%1d", I would grep for "%02d:%02d.%d". [few minutes later] And I just did. And I found that most places actually use "%02x:%02x.%x" (trace-events, hw/pci/pci.c, hw/vfio/pci.c) and only one (get_pci_host_devaddr) uses "%d" for a function (and even there "%02x" is used for a bus and a slot, not "%02d"). > >> >> >>> + devtype, pdev->name, >>> + sphb->index, PCI_SLOT(pdev->devfn), >>> + PCI_FUNC(pdev->devfn)); >>> + return buf; >>> +} >>> + >>> /* Macros to operate with address in OF binding to PCI */ >>> #define b_x(x, p, l) (((x) & ((1<<(l))-1)) << (p)) >>> #define b_n(x) b_x((x), 31, 1) /* 0 if relocatable */ >>> @@ -906,12 +961,12 @@ static void populate_resource_props(PCIDevice *d, ResourceProps *rp) >>> } >>> >>> static int spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int offset, >>> - sPAPRPHBState *sphb, >>> - const char *drc_name) >>> + sPAPRPHBState *sphb) >>> { >>> ResourceProps rp; >>> bool is_bridge = false; >>> int pci_status; >>> + char *buf = NULL; >>> uint32_t drc_index = spapr_phb_get_pci_drc_index(sphb, dev); >>> >>> if (pci_default_read_config(dev, PCI_HEADER_TYPE, 1) == >>> @@ -973,9 +1028,13 @@ static int spapr_populate_pci_child_dt(PCIDevice *dev, void *fdt, int offset, >>> * processed by OF beforehand >>> */ >>> _FDT(fdt_setprop_string(fdt, offset, "name", "pci")); >>> - if (drc_name) { >>> - _FDT(fdt_setprop(fdt, offset, "ibm,loc-code", drc_name, >>> - strlen(drc_name))); >>> + buf = spapr_phb_get_loc_code(sphb, dev); >>> + if (!buf) { >>> + error_report("Failed setting the ibm,loc-code"); >>> + return -1; >>> + } else { >> >> No need in "else". > > Yeah. > >> >>> + _FDT(fdt_setprop_string(fdt, offset, "ibm,loc-code", buf)); >>> + g_free(buf); >>> } >>> if (drc_index) { >>> _FDT(fdt_setprop_cell(fdt, offset, "ibm,my-drc-index", drc_index)); >>> @@ -1003,8 +1062,7 @@ typedef struct sPAPRFDT { >>> } sPAPRFDT; >>> >>> /* create OF node for pci device and required OF DT properties */ >>> -static int spapr_create_pci_child_dt(PCIDevice *pdev, sPAPRFDT *p, >>> - const char *drc_name) >>> +static int spapr_create_pci_child_dt(PCIDevice *pdev, sPAPRFDT *p) >>> { >>> int offset, ret; >>> char nodename[64]; >>> @@ -1017,8 +1075,8 @@ static int spapr_create_pci_child_dt(PCIDevice *pdev, sPAPRFDT *p, >>> sprintf(nodename, "pci@%d", slot); >>> } >>> offset = fdt_add_subnode(p->fdt, p->node_off, nodename); >>> - ret = spapr_populate_pci_child_dt(pdev, p->fdt, offset, p->sphb, >>> - drc_name); >>> + >>> + ret = spapr_populate_pci_child_dt(pdev, p->fdt, offset, p->sphb); >>> g_assert(!ret); >>> if (ret) { >>> return 0; >>> @@ -1033,7 +1091,6 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector *drc, >>> { >>> sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc); >>> DeviceState *dev = DEVICE(pdev); >>> - const char *drc_name = drck->get_name(drc); >>> int fdt_start_offset = 0, fdt_size; >>> sPAPRFDT s_fdt = {NULL, 0, NULL}; >>> >>> @@ -1041,7 +1098,7 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector *drc, >>> s_fdt.fdt = create_device_tree(&fdt_size); >>> s_fdt.sphb = phb; >>> s_fdt.node_off = 0; >>> - fdt_start_offset = spapr_create_pci_child_dt(pdev, &s_fdt, drc_name); >>> + fdt_start_offset = spapr_create_pci_child_dt(pdev, &s_fdt); >>> if (!fdt_start_offset) { >>> error_setg(errp, "Failed to create pci child device tree node"); >>> goto out; >>> @@ -1519,7 +1576,7 @@ static void spapr_populate_pci_devices_dt(PCIBus *bus, PCIDevice *pdev, >>> int offset; >>> sPAPRFDT s_fdt; >>> >>> - offset = spapr_create_pci_child_dt(pdev, p, NULL); >>> + offset = spapr_create_pci_child_dt(pdev, p); >>> if (!offset) { >>> error_report("Failed to create pci child device tree node"); >>> return; >>> >> >> >> -- >> Alexey > -- Alexey